Studies are in progress or are anticipated being done in the following areas: (1) On the properties and mechanism of action of 2- keto-4-hydroxyglutarate aldolase, an important enzyme in the metabolism of L-hydroxyproline by mammals which has been found to differ in many respects from other aldolases studied so far. This aldolase is also present in E. coli. Such efforts will include an examination of the subunit structure of the enzyme and also an exploration of the functional groups in the enzyme molecule which participate in the catalytic process. Comparative enzymology will be done. (2) On the nature of new reactions in the metabolism of gamma-hydroxyglutamic acid, an intermediate in L-hydroxyproline degradation by mammals. (3) On the purification and properties of enzymes involved in the conversion of L- threonine to D-1-amino-2-propanol. Biblographic references: Dekker, E.E. and Maitra, U. (1975) DL-2- Keto-4-hydroxyglutarate, Methods in Enzymology 41 (Part B), ll5. Dekker, E. E., Kobes, R.D.and Grady, S. R. (1975) 2-Keto-4-hydroxyglutarate Aldolase from Bovine Liver, Methods in Enzymology 42 (Part C), 280.